Why YOU Need a WAN Emulator

If you’re a network administrator or IT manager, you need a WAN emulator in your test toolkit. Here’s why…

Your applications are primarily running on servers at headquarters, but need to be accessed by users dispersed everywhere, from teams in regional and local offices to your sales people on the road, to your telecommuters dialed-in from home, to your retail and production sites around the world.

Application performance is obviously be sensitive to the amount of bandwidth connecting users to headquarters — only so much data can be pumped through the pipe. But what may be less obvious is that application throughput and responsiveness can be just as sensitive, if not more so, to link latency, jitter, and packet loss.

As a simple but dramatic example, opening a 10 MB file on the LAN takes less than 0.1 second. When the bandwidth is restricted to a 45 Mbps T3 line, the same file access takes 2 seconds. No surprise there, simply a matter of bandwidth. But when someone at an office across the country, even on a dedicated T3 line, tries to access the same file, it takes 9 seconds. That’s the effect of 100 ms of latency between the sites. Even worse, if you have employees in Australia, they have to wait 22 seconds. And your teams in China and India using an Internet VPN with 1% packet loss are forced to endure at least 3 minutes to open the same file no matter how much bandwidth they have. Hmmm. Or as my wife says (all too frequently), “Do something about it. NOW.”

Maybe 9 seconds for your in-country people isn’t a problem, or at least not a priority. But what if your customer reps are forced to wait 9 seconds after every data entry for their screens to refresh? Or if the file is larger than 10 MB – a CAD drawing perhaps, or an over-produced marketing presentation that the CEO is trying to download at an investor conference? Then they definitely have a problem, and so do you.

Are there solutions? Certainly. But you first you need to know what to expect so you’ll know what is and what isn’t a problem, and a way to benchmark any potential solution.

For our simple file access example, you can call your buddy at the regional office in Chicago, or even the one in Singapore, and tell him, “Download this file from the shared drive and let me know how long it takes.” But how do you test the responsiveness of your accounting system or the ERP package? Or the rollout of a new VoIP or video system?

This is where a WAN emulator makes its dramatic entrance into your life. I won’t promise that it’ll improve your love life, help your recalcitrant teen see reason, or even reduce the cost of health insurance, but it will make your work life easier so you can focus on these other problems, or at least have more time to spend on the million other projects your boss has committed you to completing before the end of the quarter.

Simply put, a WAN emulator simulates the WAN link so you can test applications in your lab, or even in your own office, and see for yourself how they’ll look to users across town or on the other side of the world.

In its simplest configuration, you plug in a server on one side of the WAN emulator, plug in a client device on the other, and specify the WAN bandwidth, latency, and packet loss rate. Packets going into one side of the WAN emulator get pushed, jostled, roughed-up, and mangled inside the box, and come out the other side looking just like they completed an arduous journey across the network. More importantly, the client and server will react exactly as if the packets had actually emerged from the dark cloud of the telecoms network or an internet VPN.

A particularly useful configuration is to plug in a WAN emulator between your own office PC and your office network. In a matter of seconds, you’ll be able to see exactly what those pesky overseas users are seeing without having to leave the comfort of your ergonomic office chair.

So you’re thinking, how much is this little bit of magic going to cost you? Because while a tool like this would be useful, even if it doesn’t help your love life, most of your budget is already spoken for with all the new applications the CEO wants implemented, leaving little money for getting those applications to actually work well.

Fortunately, the answer is that WAN emulators can be surprisingly inexpensive, particularly if you don’t need all the bells and whistles. Of course, pricing depends on the size of the links, and products that simulate T1 lines and DSL cost considerably less than those designed for monster 10 Gig links. But our basic emulators can be had for less than a couple thousand dollars, and sophisticated ones for links of up to gigabit speeds for twelve grand or less.

So now you want to know, where do you get one of these wonderful boxes? Ah…I thought you’d never ask. A number of companies make WAN emulation products (too many, if you ask me), and you probably won’t be too shocked to find that our company is one such vendor. Our Linktropy and Netropy WAN emulators simulate links from 300 bits per second (though if you’re trying to do anything on a 300 baud link, a WAN emulator is the least of your problems) up to 10 Gbps. We’ve designed the products specifically for busy people with limited budgets – making them as easy to use as possible so you can begin testing immediately without any training, while remaining a trustworthy test tool that you can rely. And with our prices, you can’t afford not to have one.